I. Field
The following description relates generally to wireless communications, and more particularly to employing dedicated reference signals in downlink transmissions.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as voice and data, Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP2, 3GPP long-term evolution (LTE), LTE Advanced (LTE-A), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations.
To facilitate coherent demodulation and decoding of a transmission sent via wireless channel, channel estimation can be employed. In one example, a channel response can be estimated by embedding a known reference signal in the transmission. The reference signal can be analyzed by a receiver to facilitate estimating the channel response, which can approximate alterations to transmitted symbols due to channel conditions. The approximate alterations can assist a receiver during symbol identification, demodulation, and decoding.